May in Kastamonu averages a daily high of 21.9°C with nights around 7.7°C. Expect roughly 13.8 wet days totalling 75.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Kastamonu is July–October.
Based on KASTAMONU, TU (1.4km), 1995–2024. 18 years of May data.